Definition Upregulation refers to an increase in the density of beta-adrenoceptors on the surface membranes and is modulated by a multitude of pharmacologic and pathophysiologic factors.  Beta-blockers cause subtype-specific upregulation such that nonselective beta-blockers increase the density of both beta1- and beta2-adrenoceptors whereas beta1-selective antagonists upregulate only beta1-adrenoceptors. As a consequence of increased sympathetic tone, […]